1) As a member of bookcrossing they all have bookcrossing.com labels for booktracking.2) They might contain underlining. In my opinion this is an advantage of a booktrading site, as opposed to merely a library.3) They are all, at a minimum, readable. There should never be missing pages.4) They will all be mailed media mail to save costs.5) They are generally highly desirable books. My inventory is generally empty.6) International: general rule is mooch 2 others to make it worth the overseas costs. Media mail surface international has been eliminated in the United States, making it more difficult to mail cheaply abroad. Having lived abroad though I understand how difficult it is to find English-language books.